Tank filling and draining system and control valve assembly therefor



Get. 22, 1968 J, 5 ELBOGEN ET AL 3,406,709

TANK FILLING AND DRAINING SYSTEM AND CONTROL VALVE ASSEMBLY THEREFOR Filed Sept. 50, 1964 JAMES S. ELBOGEN PAUL A. DEGRAAF BY I 0%,% a ,0 J ATTORNEYS INVENTORS United States Patent 3,406,709 TANK FILLIVG AND DRAINING SYSTEM AND CONTROL VALVE ASSEMBLY THEREFOR James S. Elbogen, Northridge, and Paul A. De Graaf, Los

Angeles, Calif., assignors to Parker-Hannifin Corporation, Cleveland, Ohio, a corporation of Ohio Filed Sept. 30, 1964, Ser. No. 400,334 10 Claims. (Cl. 137-389) The present invention relates generally as indicated to a tank filling and draining system and control valve assembly therefor and more particularly to an automatic bottom loading and bottom off-loading system for tank trucks and the like.

It is a principal object of the present invention to provide a fluid handling system of the character indicated in which the filling and emptying of a tank for liquid is accomplished by a unitary control valve assembly disposed at or near the bottom of the tank.

It is another object of this invention to provide in a system of the character referred to a control valve assembly which has associated therewith a jet level sensor which, when the level of liquid is therebelow, permits pressure actuation of the main inlet valve to an open position for filling of the tank through the bottom thereof and which, when the level of the fluid reaches the sensor, is effective to automatically close the main inlet valve thus to discontinue the tank filling operation despite maintenance of fluid pressure at the supply nozzle.

it is another object of this invention to provide a system of the character referred to in which the control valve assembly may be power operated to open the main inlet valve for emptying the contents of the tank therethrough.

It is another object of this invention to provide a system of the character indicated in which multiple jet level sensors (two, for example), are provided at different levels in the tank so that as the level of the liquid in the tank rises, the successive sensors progressively close the main inlet valve, thus making possible accurate control of the shutoff level.

It is another object of this invention to provide a control valve assembly in which the final closing movement of the main inlet valve thereof is snubbed or cushioned to minimize shock in the system.

It is another object of this invention to provide a control valve assembly of the character indicated which can only fail closed in the event of excessive leakage in the pilot valve lines and connections.

Other objects and advantages of the present invention will become apparent as the following description proceeds.

To the accompishment of the foregoing and related ends, the invention, then, comprise the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawing setting forth in detail a certain illustrative embodiment of the invention, this being indicative, however, of but one of the various ways in which the principle of the inventon may be employed.

In said annexed drawing:

FIG. 1 is a schematic piping diagram of a tank filling and draining system and control valve assembly therefor embodying the present invention; and

FIG. 2 is a cross-section view of the control valve assembly on enlarged scale taken substantially along the line 22, FIG. 1.

Referring now in detail to the drawing, the reference numeral 1 denotes the tank of a tank truck or the like, having an opening 2 in the bottom thereof in which is mounted a pilot operated control valve assembly 3 which, as-hereinafter explained in detail, operates as an inlet valve for filling the tank 1 when a pressure supply nozzle 4 is connected to the adapter 5 of the conduit 6 leading to said valve assembly 3. Said valve assembly 3 also functions as a tank emptying or off-loading valve through which fluid in the tank 1 is drained when the off-loading valve 7 in said conduit 6 is opened.

A pilot line 8 is connected in the conduit 6 and terminates at the jet nozzles 9 and 10 of a dual jet level sensor 11. The jet pressure is regulated by the pressure regulator 12 in the pilot line 8. The jet level sensor 11 comprises dual receivers 14 and 15 which convert the velocity heads of the jet streams shooting across from the respective nozzles 9 and 10 to a static pressure head which is effective through conduits 16 and 17 in acting on the respective pilot valves 18 and 19 to open the same. In FIG. 2 the pilot valve 19 is shown in cross-section, and it is to be understood that the other pilot valve 18 to which the receiver line 16 is connected is of the same construction.

The tank 1 is further provided with a pressure actuated vent valve 20 which is opened by operating the valve 21 to communicate through conduit 22 and shuttle valve 30 the chamber 23 of the vent valve 20 with an air pressure supply line 24 which is opened to the air tank 31 through valve 32 and interlock strap 33. Air pressure in chamber 23 acts on the plunger portion 25 of the vent valve mem ber 26 to move it away from seat 27 thus to vent the tank 1 during filling or emptying thereof. When such air pressure in chamber 23 is vented through port 28 of valve 21, the vent valve 20 is biased by spring 29 to closed position. The interlock strap 33 in solid line position vents shuttle valve 30 through valve 34 so that operation of valve 21 will actuate the shuttle valve 30 as aforesaid. When strap 33 is moved to dotted position, valve 32 vents conduit 24 and valve 34 opens communication between air tank 31 and vent valve 20 via the shuttle valve 30 which is actuated by air pressure, the left side being vented by valve 21.

Assuming that it is desired to fill the tank 1, the valve 21 is operated to open the vent valve 20 and the fluid supply nozzle 4 is connected to the adapter 5, and by reason of the shooting of jet streams across from the jet nozzles 9 and 10 to the respective jet receivers 14 and 15 pressure is built up in the receiver lines 16 and 17 to act on the plunger portions of the respective pilot valves 18 and 19 to open the main valve pressure seating chamber 35 to the interior of the tank 1 by way of the passages 36 and 37 opened by the pilot valves 18 and 19. Accordingly, fluid can escape from the chamber 35 more rapidly through said passages 36 and 37 than it can enter through the annular orifice defined between the rod 38 and the central opening 39 in the main valve member 40. Accordingly, the pressure differential between the lower and upper sides of the main valve member 40' overcomes the bias of the main valve spring 41 thus to move the main valve member 40 away from its seat 42 for flow of fluid under pressure into the tank 1. As the level of the liquid in the tank rises, to the jet level sensor 11, it first submerges the jet stream issuing from the lower nozzle 9, whereby the drop in pressure in the receiver 14 and receiver line 16 will permit the spring 45 to urge the corresponding pilot valve 18 to seated position closing passage 36 with consequent reduced rate of flow of fluid from the main valve chamber 35 into the tank 1. The resulting hydraulic unbalance causes the main valve member 40 and the main spring 41, to move toward its seat 42. When the central opening of member 40 reaches the enlarged head 46 of rod 38 a hydraulic balance is reestablished and member 40 is now in balance close to its seat. Thus, the rate of flow of fluid into the tank 1 from conduit 6 is decreased so that the level of liquid in the tank rises at a decreased rate as compared with the full open condition of the main valve member 40 when both jets were shooting across the nozzles 9 and 10 to the receivers 14 and 15. Finally, when the liquid level rises to submerge the upper jet nozzle 10 and thus results in a loss of pressure in the upper receiver 15 and receiver line 17, the other pilot valve 19 will be seated by its bias ing spring 45 to close the other passage 37 so that pressure in the chamber and below the main valve member is equalized so that the spring 41 and the resulting hydraulic unbalance can now fully close the main valve member 40 to discontinue the filling operation despite fluid pressure in the conduit 6 and in the pilot line 8. The dual jet level sensor 11 herein enables very accurate level control because of the decreased rate of rise in level as it nears the desired level when the main valve member 40 has moved partly to closed position.

Upon completion of the tank filling operation, as aforesaid, the valve 21 may be operated to vent the chamber 23 of the vent valve 20, whereupon the spring 29 acting thereon closes the same to prevent loss of liquid by sloshing and, in addition, in the case of fuel or like volatile liquids, the closing of the vent valve 20 prevents loss of liquid by evaporation.

The rod 38 aforesaid, has a pin 47 diametrically through its lower end adapted to engage and lift the main valve member 40 away from its seat 42 for draining or emptying the contents of the tank 1, and for that purpose the upper end of the rod 38 is connected to a piston 48 which moves vertically in the cylinder 49 formed as a part of the pilot valve housing 50. A branch line 51 is connected to the air line 22 downstream of the valve 21 and is communicated through the passage 52 with the lower end of cylinder 49. An on-ofi valve 53 is provided in said branch line 51.

When it is desired to off-load or empty the tank 1, the ofiF-loading valve 7 will be opened, the valve 53 will be opened, and the air control valve 21 will be operated to dotted line position, whereby air pressure in line 22 again opens the vent valve 20 as previously described and air pressure in line 51 and passage 52 moves the piston 48 and rod 38 upwardly, thus to lift the main valve member 40 through pin 46 out of engagement with its seat 42 with consequent draining of the liquid in the tank 1 through the main valve 3 and off-loading valve 7. When the desired amount of liquid has been off-loaded from the tank 1, the elf-loading valve 7 may be closed, and upon operation of the valve 21 the cylinder chamber 54 and vent valve chamber 23 are vented, whereby the spring 29 closes said vent valve 20 and the spring 55 acting on the piston 48 moves it and rod 38 to the position shown in FIG. 2, whereupon the main valve spring 41 urges the main valve member 40 to seated position.

Although there is shown herein a dual jet level sensor 11, it is to be understood that a single jet level sensor may be employed, whereby the submergence of the single jet in the liquid being admitted into the tank 1 will open a single pilot valve for venting the main valve chamber 35 so that inlet pressure may open said main valve member 40 for full flow and so that when the single jet is submerged, the pilot valve will close and the main valve member 40 will be closed by spring 41 and resulting hydraulic unbalance upon equalization of liquid pressure on opposite sides thereof.

It is to be noted further that the closing of the main valve member 40 is cushioned by reason of enlarged head portion 46 of the rod 38 entering the central opening 39 in said main valve member 40. Therefore, the last portion of the closing movement is cushioned to greater extent than when the central opening is in the region of the smaller diameter portion of the rod 38.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims, or the equivalent of such, be employed.

We therefore particularly point out and distinctly claim as our invention:

1. A control valve assembly for admitting liquid into a tank and draining liquid therefrom comprising a valve housing having a passage therethrough and a valve seat; a main valve member movable in said housing into and out of engagement with said seat to respectively prevent and permit flow of liquid through said passage; spring means biasing said main valve member toward said seat; said main valve member and housing defining a chamber on one side of said main valve member which has restricted fluid communication with the other side of said main valve member; at least two pilot valves in said housing each comprising a pilot valve member movable to open and close a bleed passage in said housing leading from said chamber into the tank; said bleed passages, when opened by the respective pilot valve members, having an aggregate and individual flow capacity exceeding that of the aforesaid restricted fluid communication whereby liquid pressure in said chamber decreases with respect to the liquid pressure acting on said other side of said main valve member thus to overcome the bias of said spring means and to move said main valve member out of engagement with said seat for flow of liquid into the tank; and at least two level sensors operative successively to move one pilot valve member to close its bleed passage upon the level of the liquid in the tank approaching a predetermined level whereby liquid pressure in said chamber increases so that said spring means biases said main valve member partway toward said seat to decrease the rate of flow of liquid into the tank and then to move the other pilot valve member to close its bleed passage upon the level of liquid in the tank reaching a predetermined level whereby fluid pressures acting on opposite sides of said main valve member are equalized so that said spring means biases said main valve member into engagement with said seat to discontinue flow of liquid into the tank.

2. A tank filling and draining system comprising a tank; a main inlet and outlet valve installed in the lower portion of said tank for flow of liquid therethrough into or from said tank, said valve having a valve member therein movable to open and close a passage through which such liquid is adapted to flow into or from said tank; said valve member being moved to open position responsive to liquid pressure acting thereon in a direction causing flow of liquid into the tank; a level sensor responsive to filling of the tank to a predetermined level to effect movement of said valve member to a position closing such passage against such liquid pressure; actuating means effective to move said valve member to a position opening such passage for draining liquid from said tank through said main valve; said main valve being of the pilot-operated type having a pilot valve which, when open, bleeds inlet pressure from a chamber behind said valve member faster than such pressure can build up through a restriction from the inlet side of said valve member whereby said valve member is moved to a position opening said passage under the influence of liquid pressure acting on the inlet side thereof; and wherein said level sensor, when the liquid level rises to such predetermined level eifects closing of said pilot valve for build up of liquid pressure in said chamber and consequent movement of said valve member to a position closing said passage; said level sensor comprising a nozzle having direct communication with the liquid on the inlet side of said valve member, and a receiver having communication with a chamber of said pilot valve effective to transform the velocity head of a jet stream from said nozzle impinging thereon to a static pressure head to open said pilot valve, such pressure head decreasing substantially when the liquid level rises to submerge the jet stream thus to permit closing of said pilot valve with consequent movement of said valve member to a position closing said passage; and another level sensor for effecting movement of said valve member to a position partially closing said passage as the liquid level approaches such predetermined level comprising another nozzle and receiver having direct communication with the liquid on the inlet side of said valve member and with another pilot valve through which liquid in said chamber is bled.

3. The system of claim 2 wherein there is a single fluid line communicating the inlet side of said valve member with both of said level sensors.

4. A tank filling and draining system comprising a tank; a main inlet and outlet valve installed in the lower portion of said tank for flow of liquid therethrough into or from said tank, said valve having a valve member therein movable to open and close a passage through which such liquid is adapted to flow into or from said tank; a chamber in said valve having restricted fluid communication with the inlet side of said valve member for providing fluid pressure effective to maintain said valve member in the closed position, a bleed passage for said chamber in direct fluid communication with said tank which when open reduces the liquid pressure in said chamber to permit opening of said valve member by fluid pressure acting on the inlet side of said valve member, a spring biased pilot valve normally closing said bleed passage, and a level sensor means in direct fluid communication with the inlet side of said valve member for supplying suflicient fluid pressure to maintain said pilot valve in open position until the liquid in the tank reaches a predetermined level.

5. The system of claim 4 wherein said level sensor means comprises a nozzle disposed at such predetermined level in said tank in such direct fluid communication With the inlet side of said valve member, a receiver having communication with said pilot valve effective to transform the velocity head of a jet stream from said nozzle impinging thereon to a static pressure head to maintain said pilot valve in open position until the liquid level rises to submerge the jet stream and reduce such static head.

6. A control valve assembly for admitting liquid into a tank comprising a valve housing having a passage therethrough and a valve seat; a main valve member movable in said housing into and out of engagement with said seat respectively to prevent and permit flow of liquid through said passage; said main valve member defining with said housing a chamber having restricted fluid communication with the inlet side of said main valve member to provide sufficient pressure in said chamber for maintaining said main valve member in engagement With said valve seat; a bleed passage having a flow capacity exceeding that of the aforesaid restricted fluid communication whereby liquid pressure in said chamber decreases with respect to the liquid pressure acting on the inlet side of said main valve member thus to move said main valve member to open position out of engagement with said seat; a spring biased pilot valve normally closing said bleed passage; and level sensor means having direct fluid communication with the inlet side of said main valve member for supplying sufiicient pressure to move said pilot valve to open position to decrease the prressure in said chamber and thus cause said main valve member to open as aforesaid for admitting liquid into the tank, said level sensor means being responsive to the liquid in the tank reaching a predetermined level to decrease the pressure supplied to said pilot valve below that necessary to keep said pilot valve open, whereby said pilot valve closes and the pressure builds up in said chamber to cause said main valve member to close.

7. The control valve assembly of claim 6 further comprising a movable plunger in said housing; a rod portion extending from said plunger through said valve member; said rod portion having an enlarged end for engagement with said valve member; and means for supplying fluid pressure to said plunger for moving said plunger and thus said main valve member away from said seat for draining of liquid from the tank.

8. The control valve assembly of claim 7 wherein said restricted fluid communication is established by a radial clearance between said rod portion and a bore in said main valve member through which said rod portion projects.

9. The control valve assembly of claim 8 wherein said rod portion is of stepped formation to provide a minimum radial clearance with said bore just prior to engagement of said main valve member with said seat so as to decelerate such movement of said main valve member.

10. The control valve assembly of claim 1 further comprising a fluid pressure actuated plunger movable in said housing toward and away from said valve seat; and a rod portion extending from said plunger through a bore in said main valve member and engageable therewith for movement of said main valve member away from said seat with such plunger thus to drain liquid from the tank.

References Cited UNITED STATES PATENTS 2,762,389 9/1956 Fraser 137-390 2,849,019 8/1958 Oliveau et a1 137-391 2,851,055 9/1958 Mosher 137-413 2,871,873 2/1959 McQueen 137-390 3,020,924 2/ 1962 Davies 137386 3,250,290 5/1966 Becht 137391 X 3,269,404 8/1966 Le Bow 137199 3,255,773 6/1966 McQueen 137414 WILLIAM F. ODEA, Primary Examiner.

DAVID R. MATTHEWS, Assistant Examiner. 

1. A CONTROL VALVE ASSEMBLY FOR ADMITTING LIQUID INTO A TANK AND DRAINING LIQUID THEREFROM COMPRISING A VALVE HOUSING HAVING A PASSAGE THERETHROUGH AND A VALVE SEAT; A MAIN VALVE MEMBER MOVABLE IN SAID HOUSING INTO AND OUT OF ENGAGEMENT WITH SAID SEAT TO RESPECTIVELY PREVENT AND PERMIT FLOW OF LIQUID THROUGH SAID PASSAGE; SPRING MEANS BIASING SAID MAIN VALVE MEMBER TOWARD SAID SEAT; SAID MAIN VALVE MEMBER AND HOUSING DEFINING A CHAMBER ON ONE SIDE OF SAID MAIN VALVE MEMBER WHICH HAS RESTRICTED FLUID COMMUNICATION WITH THE OTHER SIDE OF SAID MAIN VALVE MEMBER; AT LEAST TWO PILOT VALVES IN SAID HOUSING EACH COMPRISING A PILOT VALVE MEMBER MOVABLE TO OPEN AND CLOSE A BLEED PASSAGE IN SAID HOUSING LEADING FROM SAID CHAMBER INTO THE TANK; SAID BLEED PASSAGES, WHEN OPENED BY THE RESPECTIVE PILOT VALVE MEMBERS, HAVING AN AGGREGATE AND INDIVIDUAL FLOW CAPACITY EXCEEDING THAT OF THE AFORESAID RESTRICTED FLUID COMMUNICATION WHEREBY LIQUID PRESSURE IN SAID CHAMBER DECREASES WITH RESPECT TO THE LIQUID PRESSURE ACTING ON SAID OTHER SIDE OF SAID MAIN VALVE MEMBER THUS TO OVERCOME THE BIAS OF SAID SPRING MEANS AND TO MOVE SAID MAIN VALVE MEMBER OUT OF ENGAGEMENT WITH SAID SEAT FOR FLOW OF LIQUID INTO THE TANK; AND AT LEAST TWO LEVEL SENSORS OPERATIVE SUCCESSIVELY TO MOVE ONE PILOT VALVE MEMBER TO CLOSE ITS BLEED PASSAGE UPON THE LEVEL OF THE LIQUID IN THE TANK APPROACHING A PREDETERMINED LEVEL WHEREBY LIQUID PRESSURE IN SAID CHAMBER INCREASES SO THAT SAID SPRING MEANS BIASES SAID MAIN VALVE MEMBER PARTWAY TOWARD SIDE SEAT TO DECREASE THE RATE OF FLOW OF LIQUID INTO THE TANK AND THEN TO MOVE THE OTHER PILOT VALVE MEMBER TO CLOSE ITS BLEED PASSAGE UPON THE LEVEL OF LIQUID IN THE TANK REACHING A PREDETERMINED LEVEL WHEREBY FLUID PRESSURES ACTING ON OPPOSITE SIDES OF SAID MAIN VALVE MEMBER ARE EQUALIZED SO THAT SAID SPRING MEANS BIASES SAID MAIN VALVE MEMBER INTO ENGAGEMENT WITH SAID SEAT TO DISCONTINUE FLOW OF LIQUID INTO THE TANK. 